Wireless local area networks are previously known, such as wireless local area networks WLAN, wherein mobile terminals (clients) equipped with WLAN cards move around and, using radio signals, communicate with “access points.” A problem associated with these known wireless local area networks is the way in which a new terminal is connected to a network. Since terminals are connected to the network through a wireless connection, in practice the wireless network necessitates an arrangement to prevent unauthorized terminals from connecting to the network. Otherwise there is a risk that e.g. an outsider standing in the street might, using a wireless terminal, access a wireless local area network of an adjacent company.
In the known wireless local area networks, the use of unauthorized devices has been prevented by only allowing terminals registered in a particular network to be used therein. If a new terminal is to be used in the network, information on the particular terminal should be registered in the network in advance so that a base transceiver station of the network would be willing to communicate with the new terminal.
In the known wireless local area networks, the registration mentioned above is implemented such that each terminal has a unique identifier of its own to enable the particular terminal to be identified. Before the terminal is put to use in a wireless network, the identifier of the terminal should be entered into the wireless local area network. In practice, the identifier can be entered e.g. into a base transceiver station of the wireless local area network. When the wireless network knows the identifier identifying the terminal, the base transceiver station of the wireless network allows the terminal to access the network.